What is an Access-Point?

Access points (also called base stations) provide wireless access to a wired Ethernet network. An access point plugs into a hub, switch, or wired router and sends out wireless signals. This enables computers and devices to connect to a wired network wirelessly. Access points act a lot like cellular phone towers: you can move from one location to another and continue to have wireless access to a network. When you connect to the Internet wirelessly using a public wireless network in an airport, coffee shop, or hotel, you are usually connecting through an access point. If you want to connect your computers wirelessly and you have a router that provides wireless capability, you don't need an access point. Access points don't have built-in technology for sharing Internet connections. To share an Internet connection, you must plug an access point into a router or a modem with a built-in router.

What the access point does is to send data requests on behalf of the wireless devices that are connected to it. By doing this, their task is similar to that of a wireless router: essentially, what a wireless access point represents to a wired LAN is what a wireless router is to the Internet. However, the difference lies in the fact that the devices connected through an access point become in reality part of the LAN (as a matter of fact, other computers on the LAN don't make a distinction between the wired computers and those that are wireless).This is something really great, as it means that you can dynamically expand your wired LAN, without having to use wires. Theoretically, there's nothing you can now do over your wired network that you won't be able to do over the wireless extension to it.

A Hot Spot is a common public application of WAPs, where wireless clients can connect to the Internet without regard for the particular networks to which they have attached for the moment. The concept has become common in large cities, where a combination of coffeehouses, libraries, as well as privately owned open access points, allow clients to stay more or less continuously connected to the Internet, while moving around. A collection of connected Hot Spots can be referred to as a lily-pad network. Some people confuse Wireless Access Points with Wireless Ad-Hoc networks. An Ad-Hoc network uses a connection between two or more devices without using an access point: the devices communicate directly. An Ad-Hoc network is used in situations such as a quick data exchange or a multiplayer LAN game because it is easy to set up and does not require an access point. Due to its peer-to-peer layout, Ad-Hoc connections are similar to Bluetooth ones and are generally not recommended for a permanent installation.

Internet access via Ad-Hoc networks, using features like Windows' Internet Connection Sharing, may work well with a small number of devices that are close to each other, but Ad-Hoc networks don't scale well. Internet traffic will converge to the nodes with direct internet connection, potentially congesting these nodes. For internet-enabled nodes, Access Points have a clear advantage, being designed to handle this load.